Interventions targeting structural or contextual variables have been associated with significant reductions in problem behaviors (e.g., Celentano et al., 1998); however, the preventive value of such approaches has not been studied extensively with respect to unintended pregnancy among youth, and across time to young adulthood. School-based health clinics with a family planning component (SBHC-FPCs) may promote the use of family planning services as they (1) are embedded within schools, the only public institution with the capacity to reach a majority of youth (Satcher, 1995); (2) are designed to reduce barriers associated with accessing reproductive services (e.g., finances, confidentiality concerns; Kirby, 2002); and (3) directly or indirectly expose youth to family planning resources and services that exist in their community. Research on SBHC-FPCs and reproductive behaviors has been mixed, largely due to methodological weaknesses (Kirby, 2002). The current study aims to examine whether the presence of SBHC-FPCs in high school is associated with positive short- term effects in adolescence on (A) mediating cognitive variables (e.g., reproductive attitudes, perceived sexual norms), (B) perceived availability and use of family planning services, and (C) pregnancy risk behaviors including age of sexual initiation, number of partners, and contraceptive use. We will also investigate whether students who have access to more comprehensive SBHC-FPC services in high school have (A) greater perceived availability and use of family planning services, and (B) engage in fewer pregnancy risk behaviors including delayed age of sexual initiation, fewer number of partners, and effective contraceptive use, compared to those with less comprehensive services both in high school and later. In addition, by following adolescents as they transition into young adulthood we will be able to examine if lagged and/or carry-over effects of exposure to SBHC-FPCs persist into young adulthood and assess whether family planning behaviors and unplanned pregnancy rates differ among those who attended schools with an SBHC-FPC and those who did not. A secondary goal is to assess the role of clinic characteristics (e.g. staffing, hours, perceived cultural competence of staff) on outcome variables such as family planning self-efficacy, reproductive health seeking behaviors, and family planning behaviors and intentions. Our proposed study goes beyond earlier research by 1) developing a rigorous school matching procedure thus addressing issues associated with lack of adequate comparison schools; 2) recruiting a large sample to detect small effects; 3) using a list-assisted sample to encompass both clinic users and non-users; and 4) measuring use of all family planning providers, which will allow us to capture substitution effects. Findings will increase understanding of the effects f SBHC-FPCs on reproductive health-seeking behavior and effective SBHC-FPC services. Additionally, results will provide important data that can be used in efforts to help better understand how access to medical services more generally influences health behaviors.